Grinders for grinding cutter blades



I June l0, 1958 Filed Feb. '13. 1956 B. R. ANDRUs A 2,837,877

GRINDERS FOR GRINDING CUTTER BLADES 2 Sheets-Sheet 1 l June 10, 1958 B.R. ANDRUS GRINDERS FOR GRINDING CUTTER BLADES Filed Feb. 173. 195e 2Sheets-Sheet 2 INVENTOR.

BURTON R. ANDRUS ATTORN EY S blade being ground.

GRHJDERS FUR GRINDNG CUTTER BLADE Burton R. ndrus, Eugene, Oreg.

Application February 13, 1956, Serial No. 564,982

l tlaims.` (Cl. 51143) This invention relates to improvements ingrindersfor grinding cutter blades, and it is particularly adapted tothe grinding of blades used in jointers, planers, chipping machines andthe like.

Theprimary objectief the invention is to employ an endless grinding beltfor sharpening cutter blades and the like.

A further object of this invention is to mount the grinding head upon amachine consisting of arbase frame having a moving carriage associatedtherewith for moving the blade to be sharpened relative to the grindinghead. i

Another object of the invention is to provide means of adjusting thegrinding belt to grind the blade to form either a flat Vor hollow groundcutting edge by adjusting the grinding head about a vertical axis inrelation to the A still further obje'ctof this invention is to so mountthe grinding head so as to employ the entire width of th grinding beltwhile grinding the blade.

A further object of this invention is to provide means within thegrinder head for maintaining a predetermined tension on the grindingbelt.

Other objects and advantages will become apparent in the followingspecification when considered in the light of the attached drawings, inwhich:

4Figure 1 is an end elevation of the machine constructed according tothe invention.

Figure 2 is a front elevation of the machine shown in" Y Figure 1. v

Figure 3 is an enlarged fragmentary sectional view of the grinding head`mechanism, taken on the line 3-3 of .f Figure l, looking in thedirectionv of. the arrows.

.Figure Zlis an enlargedl fragmentary sectional View of the :grindinghead assembly, taken on the line 4-4 of Y ','Figure l, looking in thedirection of the arrows.

. Figure 5 is a fragmentary sectional view of the base.ofthe-grindingmechanisim Vtaken on theline 5--5 ofV Figure l, lookingin the direction of the arrows.

Figure 6 is an enlarged fragmentary sectional-view illustrating how thebladeis mounted to the blade holding base associated with the machine,taken on the line A 6--6 of Figure'2, looking in the direction ofthearrows.

Figure 7 is an enlarged fragmentary sectional view, taken on the line7-7 of Figure l, looking inthe direction of the arrows.

sans?? 2 reference numerals indicate like parts throughout the severalfigures, the reference numeral 15 indicates a base frame on which theremainder of the construction is mounted. A movable carriage 16 isslidably mounted to a rail 17 lixedly secured to the frame 15 by abracket 13, as best illustrated in Figure 1. T he carriage 16 may beslidably mounted on the rail 17 by a V-shaped groove 19 formed under aledge Ztl on the carriage 16, the groove 19 riding on a V-shaped tongue21 formed on an upper edge of the rail 17. The lower edge 22 of the rail17 being adapted to engage a surface 23 of the carriage 15 formaintaining the carriage 16 in alignment with the rail 17. The carriage16 is moved longitudinally Vthe brackets 31. The purpose of thisadjustment will be described later on.

An arm 36 extends downwardly from the carriage 16..

and adjacent the chain 24, as best illustrated in Figures l and 2. Thearm 36 has a slot 37 formed therein which is adapted to receive theroller 3S which is xedly secured to the chain 2d by stub shaft 33A. Asthe chain 24 is rotated about its sprockets 25 and 26 the roller 38 iscarried therewith and moves the arm 36, together with the carriage 16,longitudinally of the base 15 and the r'ail ,v

17. ,The` chain 24 is driven by the shaft 23, which in turn is driven by the chain 28A from a motor (not shown) within the base 15.

A cutter bladeC holding or supporting base 39 is pivotallymountedlongitudinally of the carriage 16 in the following manner; YUpwardly extending legs or brackets d'and 40A are adapted to receivestud bolts 41 and 41A, which are threaded into ends d2 and 42A of thebase 39, as best illustrated in Figures vl, 2, 7 and 8. Theupwardly-extending legs 4t? is adapted to be adjusted transversely ofthecarriage 16, referring particularly to Figures 7 and-8, the base ltlB ofthe leg 4d is bolted to the carriage 15 by the bolts 43 by slots 44 inthe base vides -anaccurate and line adjustment of the blade holdg Figure8 is an enlarged fragmentary sectional View of V 'the mechanism foradjusting the angle` of the base andk blade passing under the grinder,taken on the line 8 3 of Figure 2, looking in the direction yof thearrows.

Figure 9 is a diagrammatical view of the blade and its holding base,illustrating how the longitudinal axis of the blade and base is offsetin regards to the direction of vtravel of the base under the grindingunit.

Figure 10 is an enlarged fragmentary sectional View yof a bearingmounting, taken on the line 10T-10 of Fig- C ,under the grinding belt87.

ing base 39 transversely of the carriage 1,6.

Referringk to Figure 9,-Vthe center -line of the carriage 16 isindicated by numeral d8. From this center line 4S itjcan be seen how theblade base 39 is shifted off its centerl line of travel. The object ofthis adjus'tment-is to position the cutter blade C being ground so as toshiftA its position under a grinding belt S7 in the operation of thegrinder G.

The elevation of end 42 is also adjustable so as vto permit leveling ofthe base 39 and the cutter blade This is accomplished by adjusting bolt49 which has an eye 50 formed thereon adapted to pass around the studbolt 41. The adjusting bolt i9 passes through a bracket 51 forming theupper part of the leg di), referring particularly to Figure 7, so thatthe endV 42 of the base 39 can be raised or lowered after which the capscrew 41 is locked, holding the same in this adjusted position,completing the vertical adjustment of the base 39 as desired.

The hold down cap screw 43 locks the leg 40 tightly down against thecarriage dafter the transverse adjust- Patented .lune 1Q, 195% assis-rrpart of the base 39 and are adapted to engage the edge 56 of the cutterblade C, as best illustrated in Figure 6.

This provides a fine accurate adjustment of the blade C. Before thesetting up of the cap screws 41 and 41A, the angle of the cutting edge57 of the blade C is determined by the adjustment of the base 39 aboutthe cap screws 4I and 411A by way of the adjusting rod 58, whose one endis pivotally mounted at 59 to the arm 6@ forming part of the base 39,and secured to the ears 61 forming part of the carriage i6 by theadjusting rods 62. When this adjustment has been cornpleted the capscrews 4l and 41A are tightened.

Referring to Figures l, 3'and 4, the grinding head unit G will now bedescribed. This unit consists of a base 63 mounted upon the top 15A ofthe frame 15 of the machine. turn has a base plate 65 forming partthereof. The base plate 65 is supported upon the legs 66 operatingwithin the grooves 67, as best illustrated in Figure 3.

Extending downwardly from the base 65 is a threaded boss 63 into whichis threaded the adjusting screw 69,V

gooseneck pedestal 75. The gooseneck pedestal has f a base 76 which issupported by the base 63 by cap screws 77, referring particularly toFigures 3 and 5.v

VThe vertical movable base 73 is slidably mounted to the base 74 onguideways 78, referring particularly'to Figure 4, and its verticalelevation is determined by a screw 79 which is journalled-within thebracket 80 forming part of the base 73. This screw 79 'is threaded intothel bracket 8l forming part of the base plate 74, referringparticularly to Figure 3. By rotating a hand wheel 82, forming party ofthe fscrew 79, the base 73 can be raised or lowered.

A motor 83 is fixedly secured to the base73 by bolts 34, referring toFigure 4. A driving belt pulley 85 iskeyed to the shaft S6 of the motor83 and is adapted to drive a grinding belt 87. The belt 87 is ,alsotrained about an idler pulley 88. The idler pulley 88 is fiXedlyVmounted" to VVa shaft 89, which in turn is journalled within a bearingsupport 99. The bearing support 90 is pivotally connected to the base 73by arms 91, which are'pivotally connected to the bracket 92, as bestillustrated in Figures l, 2 and 4. Y

lReferring to Figure l, the bearing 90 is held in a raised position bythe spring 93, which has one of its'v ends secured to the arm 94 and itsopposite end to the arm 95 forming` part of the bearingV 90. This placesa constant tension on the grinding belt 87. A handle 96 is ixedlysecured to the bearing 99 and is adapted to pull the bearing downagainst the spring 93 when removing and replacing the belt 87.

ln thedrawings, the grinding head unit G is shown in position for hollowgrinding the blade C as indicated at 57, Figure 6. When the grinder G isbeing used for grinding a flat cutting edge to the blade C, the base 76is moved to the broken line position, as indicated in Figures 3 and 5,causing the plane of the pulley S5 to take a position parallel to themovement to the length ot-the blade C and carriage I6.

f In order to centralize the position of the grinding belt 87 midway thetravel of the blade C being ground, the base 63 is of suicient length toallow the resetting of rfhe base 63 consists of a table 64, which inlthe grinding head G, as indicated by the broken lines 97 in the abovefigures.

There is still another way of centering the grinding unit G to themovement of the cutter blade C by adjusting the bearings 29 and 3l) onthe brackets 31 shifting the position of the chain 24 to either one sideor the other of the grinding machine in general.

While I have shown the grinding head G arranged at 90 degrees to theblade C being hollow ground, I find best results are obtained when setat about a 60 degree angle from the blade C, although I would not wishto be limited to any particular angle of operation.

l will now describe the operation of this new and improved bladegrinding machine. The blade C to be conditioned is bolted to the base 39by the bolts 53. The set screws 54 are adjusted to align the blade C inregards to the base 39, thereby providing a line adjustment inpositioning the blade C-relative to the base 39. The cap screws 41 and41A are loosened together with the cap screws 43 and 52. At this pointthe angle of the base 39 and blade C in regards to the face of thegrinding belt S7 is determined by the adjusting rod 58, which isadjusted by the adjusting nut 62 positioning the blade C at the properangle for the bevel to be i created on the cuttingedge 57 of the blade.The center can be made more or less alternately with one another untilthe proper adjustment has been arrived at. After .these adjustments arecompleted, the cap screws 4l, 41A, d3 and 52'. are-tightened, clampinglthe whole assembly together. Y

The next setting will be the grinding head G itself, and this isaccomplished by adjusting the base 76 about the cap screw 77, observingthe gauge marks 99 to determine the angle at which the sanding belt 87is to operate in regards to the cutting edge 57 of the blade C as abovedescribed, then by adjusting the hand wheel S2, the grinding belt 87 canbe brought down against the cutting edge of the blade C to where it willbegin to grind the same.

T he chain 24 will move the carriage ldback and forth of the machinebringing the full length of the blade C in cnntact with the grindingbelt G, the grinding operation taking place until the entire length ofthe blade C has been ground to the desired shape.`

With this grinding maehinethe belt 87 can be eliminated, together' withVthe pulley and a grindingV wheelY (not shown) attached to the shaft S6of the motor, but many advantages have been found in using a grindingbelt 87 instead of a wheel in conditioning the cutter blades C. Y Havingthus described the preferred embodiment of the invention, it shculd beunderstood that numerous modifications and structural adaptations may beresorted to without departing from the scope of the appended claims.

Vvhat is claimed is: l. A cutting blade grinding machine comprising anciengated base, a pair of spaced'apart parallel legs sej cured to saidoase and extending transversely thereof, said legs having horizontalgrooves formed in the adjacent aaamevv movement on said upright plate,control means extending between said vertical base plate and saidupright plate for sliding said vertical base plate with respect to saidupright plate, a motor tixed to said vertical base plate with the axisthereof parallel to said table, a drive pulley on said motor, an idlerpulley, means mounting said idler pulley to said vertical base forswinging movement on a horizontal pivot, means biasing said idler pulleyaway fromsaid drive pulley, an endless grinding belt trained over saididler and said drive pulleys, and longitudinally movable means on saidbase for supporting and moving work with respect to said grinding belt.

2. A device as claimed in claim l wherein said last named means includesmeans for transversely adjusting the Work toward and away from saidgrinding belt.

3. A device as claimed in claim 1 wherein said last named means includesmeans for longitudinally pivotally adjusting the Work with respect tosaid grinding belt.

4. A device as claimed in claim 1 wherein said last named means includesmeans for vertically adjusting the work with respect to said grindingbelt.

References Cited in the tile of this patent UNITED STATES PATENTS

